Field of the Invention
This invention relates to a contact and a connector including the contact.
Description of the Related Art
As shown in FIGS. 22 to 24, conventionally, there has been proposed a female terminal fitting 910 formed by integrally assembling a terminal body 911 which is formed by bending a conductive metal plate and includes a terminal fitting portion 912 and a wire connection portion 913, and an elastic contact body 925 which is a separate component from the terminal body 911 and is formed by bending a conductive metal plate (see Japanese Laid-Open Patent Publication (Kokai) No. H08-250178). The terminal fitting portion 912 has a box shape having a horizontally long rectangular cross-section, and has an insertion opening 916 formed in a front end thereof for allowing a male terminal fitting, not shown, to be inserted. A ceiling plate 918 of the terminal fitting portion 912 is formed with a pair of tab contact portions 918A which protrude downward. The pair of tab contact portions 918A each have a semi-cylindrical shape, and extend in a front-rear direction (see FIGS. 22 and 23). A bottom plate 914 is formed with an excessive bending-preventing section 923 curving upward. The excessive bending-preventing section 923 is a part for preventing an elastic bending section 928, described hereinafter, from being excessively bent.
The wire connection portion 913 includes an insulation barrel 913A and a wire barrel 913B. The insulation barrel 913A is connected to a resin coated part of a wire, not shown, and the wire barrel 913B is connected to the core of the wire.
The elastic contact body 925 is formed by bending a plate having a rectangular shape. A front end portion of the elastic contact body 925 is an engaging portion 926 forming a flat plate shape. A rear end portion of the elastic contact body 925 is formed with a holding portion 927 by bending the rear end portion into a U shape, as viewed from the side. The holding portion 927 is formed by an upper plate portion 927A, a rising portion 927B, and a lower plate portion 927C. The holding portion 927 has a dimension in the front-rear direction which is set to be slightly smaller than a spacing between a front stopper 920F and a rear stopper 920R of the terminal fitting portion 912. The upper plate portion 927A is arranged between the front stopper 920F and the rear stopper 920R of the terminal fitting portion 912 in a manner immovable in the front-rear direction. Further, the dimension of the holding portion 927 in a height direction is set to be equal to a spacing between the bottom plate 914 and a protection plate 919 of the terminal fitting portion 912. The upper plate portion 927A is in contact with the protection plate 919 and the lower plate portion 927C is in contact with the bottom plate 914 (see FIG. 22), whereby the elastic contact body 925 is held within the terminal fitting portion 912 in a manner immovable in a vertical direction.
The elastic bending section 928 is formed by bending a portion of the elastic contact body 925 between the engaging portion 926 and the holding portion 927 such that the portion is caused to curve upward. A tab contact portion 928A protruding upward is formed on the top of the elastic bending portion 928.
Right and left end portions of the engaging portion 926 of the elastic contact body 925 extend forward under pressing portions 922 of the terminal fitting portion 912 in a manner movable in the front-rear direction.
When a tab (not shown) of the male terminal fitting is inserted between the tab contact portions 918A of the terminal fitting portion 912 and the tab contact portion 928A of the elastic contact body 925, the elastic bending portion 928 is bent, whereby the tab of the male terminal fitting is sandwiched between the tab contact portions 918A of the terminal fitting portion 912 and the tab contact portion 928A of the elastic contact body 925. A constant contact force is generated between the tab of the male terminal fitting and the tab contact portions 918A of the terminal fitting portion 912, and between the tab of the male terminal fitting and the tab contact portion 928A of the elastic contact body 925, respectively, by action of a returning force of the elastic bending portion 928. The tab of the male terminal fitting is brought into line contact with the tab contact portions 918A, and is brought into point contact with the tab contact portion 928A.
Usually, the elastic contact body 925 is made of stainless steel, and the terminal body 911 is made of copper or copper alloy. Therefore, electric current mainly flows via a contact portion between the tab of the male terminal fitting and the tab contact portions 918A of the terminal fitting portion 912.
If the female terminal fitting 910 or the male terminal fitting is low in shaping accuracy, or if an electric wire connected to the wire connection portion 913 of the female terminal fitting 910 is pulled, misalignment may occur between the female terminal fitting 910 and the male terminal fitting which are in a connected state.
For example, if the electric wire connected to the wire connection portion 913 of the female terminal fitting 910 is pulled, causing inclination of the tab contact portions 918A of the female terminal fitting 910 with respect to the tab of the male terminal fitting, a parallel positional relationship between the tab of the male terminal fitting and the tab contact portions 918A of the female terminal fitting 910 is lost, which reduces a contact area between the tab of the male terminal fitting and the tab contact portions 918A of the female terminal fitting 910. When the contact area between the tab of the male terminal fitting and the tab contact portions 918A of the female terminal fitting 910 is reduced, the contact resistance is largely changed, so that there is a fear of reduction of the contact reliability.